Which subject became difficult for Margie because of the mechanical teacher's fault?

Correct answer: Geography

Margie’s difficulty was connected with Geography. The Geography sector of her mechanical teacher had been adjusted incorrectly, so it was giving her tests and lessons at a speed that did not suit her level. As a result, her performance became poor, and she began to feel that the subject was difficult. The problem was not that she had no ability to learn Geography.

Therefore, option C, Geography, is correct. History, English, and Music are not identified in this incident as the subject affected by the faulty adjustment. The important reasoning is to connect the mechanical teacher’s malfunction with the subject being taught at the wrong pace. Once the county inspector repaired and adjusted the machine, the immediate difficulty was addressed.